Check: If there are unread mail for root issue warning

[lzap]

We have many crons, they end up in root mail folder (or file technically).

[kgaikwad]

@lzap ,
I would like to know that how you find out unread mails from any user mail file like /var/spool/mail/root.
For this, are you using any mail client like mailutils or mailx.

[lzap]

Hello, root mail is stored in mbox file (regular text file) in /var/spool/mail/root, so if you find this file and it has non-zero size, you got some mail. To count number of emails, this hack is possible:

egrep '^Message-Id' /var/spool/mail/root | wc -l

If you need to know (rough) number of emails. Now if you read them (you can use mutt or mailx to do that) they will disappear from the file. Example session:

[root@fido ~]# yum install mailx^C
[root@fido ~]# sendmail root 
Subject: Test

This is a test
CTRL+D
[root@fido ~]# cat /var/spool/mail/root 
From root@fido.example.com  Thu Apr 20 14:36:31 2017
Return-Path: <root@fido.example.com>
X-Original-To: root
Delivered-To: root@fido.example.com
Received: by fido.example.com (Postfix, from userid 0)
        id 08CF728F55C2; Thu, 20 Apr 2017 14:36:31 +0200 (CEST)
Message-Id: <20170420123631.08CF728F55C2@fido.example.com>
Date: Thu, 20 Apr 2017 14:36:29 +0200 (CEST)
From: root@fido.example.com (root)

fdsfsdf

From root@fido.example.com  Thu Apr 20 14:36:53 2017
Return-Path: <root@fido.example.com>
X-Original-To: root
Delivered-To: root@fido.example.com
Received: by fido.example.com (Postfix, from userid 0)
        id C5FA628F55C2; Thu, 20 Apr 2017 14:36:53 +0200 (CEST)
Subject: Test
Message-Id: <20170420123653.C5FA628F55C2@fido.example.com>
Date: Thu, 20 Apr 2017 14:36:41 +0200 (CEST)
From: root@fido.example.com (root)

This is a test
CTRL+D

[root@fido ~]# mail
Heirloom Mail version 12.5 7/5/10.  Type ? for help.
"/var/spool/mail/root": 2 messages 2 new
>N  1 root                  Thu Apr 20 14:36  12/407   
 N  2 root                  Thu Apr 20 14:36  14/435   "Test"
& n
Message  1:
From root@fido.example.com  Thu Apr 20 14:36:31 2017
Return-Path: <root@fido.example.com>
X-Original-To: root
Delivered-To: root@fido.example.com
Date: Thu, 20 Apr 2017 14:36:29 +0200 (CEST)
From: root@fido.example.com (root)
Status: R

fdsfsdf

& d
& n
Message  2:
From root@fido.example.com  Thu Apr 20 14:36:53 2017
Return-Path: <root@fido.example.com>
X-Original-To: root
Delivered-To: root@fido.example.com
Subject: Test
Date: Thu, 20 Apr 2017 14:36:41 +0200 (CEST)
From: root@fido.example.com (root)
Status: R

This is a test
CTRL+D

& q
Held 1 message in /var/spool/mail/root
[root@fido ~]# cat /var/spool/mail/root 
From root@fido.example.com  Thu Apr 20 14:36:53 2017
Return-Path: <root@fido.example.com>
X-Original-To: root
Delivered-To: root@fido.example.com
Received: by fido.example.com (Postfix, from userid 0)
        id C5FA628F55C2; Thu, 20 Apr 2017 14:36:53 +0200 (CEST)
Subject: Test
Message-Id: <20170420123653.C5FA628F55C2@fido.example.com>
Date: Thu, 20 Apr 2017 14:36:41 +0200 (CEST)
From: root@fido.example.com (root)
Status: RO

This is a test
CTRL+D

[root@fido ~]# mail
Heirloom Mail version 12.5 7/5/10.  Type ? for help.
"/var/spool/mail/root": 1 message
>   1 root                  Thu Apr 20 14:36  15/446   "Test"
& d
& q
[root@fido ~]# cat /var/spool/mail/root 
[root@fido ~]# ls -la /var/spool/mail/root
-rw-------. 1 root mail 0 20. dub 14.37 /var/spool/mail/root
[root@fido ~]# 

[kgaikwad]

@lzap, thank you for providing information.

Additional to above details, I have few things which I would like to ask for my understanding.

• Except disk spacing consumption, what are the possible causes of unread mails.
• What do you think, it will have an impact on any process like upgrade?

[lzap]

This has no impact on upgrade, we should have a separate free space checker perhaps.

[swapab]

Redmine issue: http://projects.theforeman.org/issues/20148